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The Flu


Updated May 16, 2014

Flu Virus Vaccine

Flu shots are made from killed flu viruses.

Image: US Centers for Disease Control (PD)


The flu - caused by the influenza virus.
The flu virus may be classified as either influenza A, B or C. Only influenza A and B cause illness in humans.

Flu Season:

Late fall to early spring, most prevalent from December to March.

Who is Affected:

People of all ages can get the flu. Children, the elderly and people with weakened immune systems are most susceptible and more likely to have serious complications.


The flu is caused by the influenza virus. There are many different strains of the virus and they mutate frequently. This is why people continue to come down with the flu year after year.

How the Flu is Spread:

Influenza is spread by droplets from the mouth and nose. If a person with the flu sneezes or coughs, the virus is then released into the air and onto any objects around him including whatever the person touches. When someone else breathes in those droplets or touches any object that has the virus on it then touches his nose, mouth or eyes, the virus spreads.

The flu can be spread from 1 day before symptoms appear to 5 days after becoming sick. It is possible to spread the flu before you even know you have it.

What to Expect:

The flu can last anywhere from 2-7 days, with 4-5 days being the most common. People with the flu usually run a fever, have aches and pains throughout their bodies, feel exhausted, experience severe headaches and may have cold symptoms. These symptoms come on more rapidly than they do with a cold. People with the flu are typically unable to perform daily activities due to the illness.

If you believe you have the flu and are at high risk for complications, or will be around someone who is, you should contact your health care provider as soon as you develop symptoms. He or she can perform a flu test or diagnose you based on your symptoms and determine the best course of treatment for you.

Is There a Cure?:

There is no cure for the flu. There are some prescription antiviral medications, such as Tamiflu, that may help shorten the duration of the illness. However, Tamiflu is only effective if taken within the first 48 hours of the onset of symptoms. Your doctor will determine if these medications are right for you.

What About the Flu Shot?:

There is a flu vaccine that is typically available starting in August or September. The flu vaccine provides protection against the strain of flu that researchers believe is most likely to cause illness during flu season. However, because the influenza virus mutates so frequently, the vaccine may not provide complete immunity to the flu.

What Should I Do if I Have the Flu?:

The most important thing to do when you get the flu is to get plenty of rest. Because the flu is highly contagious, you should avoid other people until you are feeling better. Other tips for taking care of yourself when you have the flu:

  • Drink plenty of fluids - water and sports drinks
  • Take over the counter medications to relieve symptoms
  • Sleep as much as possible
  • Eat when you feel like it, but focus on staying hydrated if you aren't hungry
  • Avoid alcohol and tobacco use

Learn More About Your Flu Treatment Options


"Key Facts about Influenza and the Influenza Vaccine." Centers for Disease Control and Prevention. 30 Aug 06. Centers for Disease Control and Prevention. 27 Feb 07.

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